scholarly journals Trained Immunity-Based Vaccines: A Ready-to-Act Strategy to Tackle Viral Outbreaks

2022 ◽  
Author(s):  
Laura Conejero ◽  
Paula Saz-Leal ◽  
José Luis Subiza
Keyword(s):  
Public Health ◽  
Innate Immunity ◽  
Immune Responses ◽  
Immune Cells ◽  
Innate Immune Cells ◽  
Virus Spread ◽  
Emerging Viruses ◽  
Trained Immunity ◽  
Alternative Approaches ◽  
Special Mention

Viral outbreaks have become significant threats to global human public health. New emerging viruses, pathogen mutations, and even the progressive loss of efficacy in some existing vaccines are behind this problem, which is amplified by the rapid virus spread given the ease of current mobility. Taking into account that these outbreaks arise in the absence of conventional effective vaccines, alternative approaches based on trained (innate) immunity are being considered. This immunity is dependent on a functional reprogramming of innate immune cells, leading to an enhanced nonspecific response towards different pathogens, including viruses. Trained immunity-based vaccines (TIbVs), defined as vaccine formulations containing trained immunity inducers, could be used during viral outbreaks to confer non-specific protection but also to enhance adaptive specific immune responses. In this chapter, we aim to illustrate how TIbVs could tackle the above-mentioned situations derived from viral outbreaks, reviewing the potential of available TIbVs in such urgent situations with a special mention to COVID-19.

scholarly journals Trained Innate Immunity Not Always Amicable

2019 ◽  
Vol 20 (10) ◽  
pp. 2565 ◽  
Author(s):  
Marcin Włodarczyk ◽  
Magdalena Druszczyńska ◽  
Marek Fol
Keyword(s):  
Gene Expression ◽  
Immune Response ◽  
Innate Immunity ◽  
Immune Cells ◽  
Innate Immune ◽  
Cell Physiology ◽  
Innate Immune Cells ◽  
Trained Immunity ◽  
Increased Strength ◽  
Immunological Protection

The concept of “trained innate immunity” is understood as the ability of innate immune cells to remember invading agents and to respond nonspecifically to reinfection with increased strength. Trained immunity is orchestrated by epigenetic modifications leading to changes in gene expression and cell physiology. Although this phenomenon was originally seen mainly as a beneficial effect, since it confers broad immunological protection, enhanced immune response of reprogrammed innate immune cells might result in the development or persistence of chronic metabolic, autoimmune or neuroinfalmmatory disorders. This paper overviews several examples where the induction of trained immunity may be essential in the development of diseases characterized by flawed innate immune response.

scholarly journals Natural Killer Dendritic Cells Enhance Immune Responses Elicited byα-Galactosylceramide-Stimulated Natural Killer T Cells

2013 ◽  
Vol 2013 ◽  
pp. 1-18 ◽  
Author(s):  
Sung Won Lee ◽  
Hyun Jung Park ◽  
Nayoung Kim ◽  
Seokmann Hong
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Immune Responses ◽  
Natural Killer ◽  
Immune Cells ◽  
Tumor Antigens ◽  
Nkt Cells ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Natural Killer T

Natural killer dendritic cells (NKDCs) possess potent anti-tumor activity, but the cellular effect of NKDC interactions with other innate immune cells is unclear. In this study, we demonstrate that the interaction of NKDCs and natural killer T (NKT) cells is required for the anti-tumor immune responses that are elicited byα-galactosylceramide (α-GC) in mice. The rapid and strong expression of interferon-γby NKDCs afterα-GC stimulation was dependent on NKT cells. Various NK and DC molecular markers and cytotoxic molecules were up-regulated followingα-GC administration. This up-regulation could improve NKDC presentation of tumor antigens and increase cytotoxicity against tumor cells. NKDCs were required for the stimulation of DCs, NK cells, and NKT cells. The strong anti-tumor immune responses elicited byα-GC may be due to the down-regulation of regulatory T cells. Furthermore, the depletion of NKDCs dampened the tumor clearance mediated byα-GC-stimulated NKT cellsin vivo. Taken together, these results indicate that complex interactions of innate immune cells might be required to achieve optimal anti-tumor immune responses during the early stages of tumorigenesis.

scholarly journals The Effects of Trained Innate Immunity on T Cell Responses; Clinical Implications and Knowledge Gaps for Future Research

2021 ◽  
Vol 12 ◽  
Author(s):  
Dearbhla M. Murphy ◽  
Kingston H. G. Mills ◽  
Sharee A. Basdeo
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Cells ◽  
T Cell Responses ◽  
Innate Immune ◽  
Metabolic Reprogramming ◽  
Innate Immune Cells ◽  
Peripheral Tissues ◽  
Trained Immunity ◽  
Cell Responses

The burgeoning field of innate immune training, also called trained immunity, has given immunologists new insights into the role of innate responses in protection against infection and in modulating inflammation. Moreover, it has led to a paradigm shift in the way we think about immune memory and the interplay between innate and adaptive immune systems in conferring immunity against pathogens. Trained immunity is the term used to describe the medium-term epigenetic and metabolic reprogramming of innate immune cells in peripheral tissues or in the bone marrow stem cell niche. It is elicited by an initial challenge, followed by a significant period of rest that results in an altered response to a subsequent, unrelated challenge. Trained immunity can be associated with increased production of proinflammatory mediators, such as IL-1β, TNF and IL-6, and increased expression of markers on innate immune cells associated with antigen presentation to T cells. The microenvironment created by trained innate immune cells during the secondary challenge may have profound effects on T cell responses, such as altering the differentiation, polarisation and function of T cell subtypes, including Th17 cells. In addition, the Th1 cytokine IFN-γ plays a critical role in establishing trained immunity. In this review, we discuss the evidence that trained immunity impacts on or can be impacted by T cells. Understanding the interplay between innate immune training and how it effects adaptive immunity will give insights into how this phenomenon may affect the development or progression of disease and how it could be exploited for therapeutic interventions or to enhance vaccine efficacy.

scholarly journals Therapies Targeting Trained Immune Cells in Inflammatory and Autoimmune Diseases

2021 ◽  
Vol 11 ◽  
Author(s):  
Cristina Municio ◽  
Gabriel Criado
Keyword(s):  
Autoimmune Diseases ◽  
Immune Cells ◽  
Inflammatory Diseases ◽  
Cell Metabolism ◽  
Innate Immune ◽  
Epigenetic Reprogramming ◽  
Innate Immune Cells ◽  
Tissue Destruction ◽  
Specific Stimulus ◽  
Trained Immunity

The concept of trained immunity has recently emerged as a mechanism contributing to several immune mediated inflammatory conditions. Trained immunity is defined by the immunological memory developed in innate immune cells after a primary non-specific stimulus that, in turn, promotes a heightened inflammatory response upon a secondary challenge. The most characteristic changes associated to this process involve the rewiring of cell metabolism and epigenetic reprogramming. Under physiological conditions, the role of trained immune cells ensures a prompt response. This action is limited by effective resolution of inflammation and tissue repair in order to restore homeostasis. However, unrestrained activation of innate immune cells contributes to the development of chronic inflammation and tissue destruction through the secretion of inflammatory cytokines, proteases and growth factors. Therefore, interventions aimed at reversing the changes induced by trained immunity provide potential therapeutic approaches to treat inflammatory and autoimmune diseases like rheumatoid arthritis (RA). We review cellular approaches that target metabolism and the epigenetic reprogramming of dendritic cells, macrophages, natural killer cells, and other trained cells in the context of autoimmune inflammatory diseases.

scholarly journals The cell biology of inflammation: From common traits to remarkable immunological adaptations

2020 ◽  
Vol 219 (7) ◽  
Author(s):  
Helen Weavers ◽  
Paul Martin
Keyword(s):  
Innate Immunity ◽  
Cell Division ◽  
Membrane Trafficking ◽  
Immune Cells ◽  
Cell Biology ◽  
Foreign Bodies ◽  
Cell Types ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Starting Point

Tissue damage triggers a rapid and robust inflammatory response in order to clear and repair a wound. Remarkably, many of the cell biology features that underlie the ability of leukocytes to home in to sites of injury and to fight infection—most of which are topics of intensive current research—were originally observed in various weird and wonderful translucent organisms over a century ago by Elie Metchnikoff, the “father of innate immunity,” who is credited with discovering phagocytes in 1882. In this review, we use Metchnikoff’s seminal lectures as a starting point to discuss the tremendous variety of cell biology features that underpin the function of these multitasking immune cells. Some of these are shared by other cell types (including aspects of motility, membrane trafficking, cell division, and death), but others are more unique features of innate immune cells, enabling them to fulfill their specialized functions, such as encapsulation of invading pathogens, cell–cell fusion in response to foreign bodies, and their self-sacrifice as occurs during NETosis.

scholarly journals Stress Hyperglycemia, Insulin Treatment, and Innate Immune Cells

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Fangming Xiu ◽  
Mile Stanojcic ◽  
Li Diao ◽  
Marc G. Jeschke
Keyword(s):  
Insulin Resistance ◽  
Innate Immunity ◽  
Immune System ◽  
Critical Illness ◽  
Immune Cells ◽  
Innate Immune System ◽  
Insulin Treatment ◽  
Innate Immune ◽  
Morbidity And Mortality ◽  
Innate Immune Cells

Hyperglycemia (HG) and insulin resistance are the hallmarks of a profoundly altered metabolism in critical illness resulting from the release of cortisol, catecholamines, and cytokines, as well as glucagon and growth hormone. Recent studies have proposed a fundamental role of the immune system towards the development of insulin resistance in traumatic patients. A comprehensive review of published literatures on the effects of hyperglycemia and insulin on innate immunity in critical illness was conducted. This review explored the interaction between the innate immune system and trauma-induced hypermetabolism, while providing greater insight into unraveling the relationship between innate immune cells and hyperglycemia. Critical illness substantially disturbs glucose metabolism resulting in a state of hyperglycemia. Alterations in glucose and insulin regulation affect the immune function of cellular components comprising the innate immunity system. Innate immune system dysfunction via hyperglycemia is associated with a higher morbidity and mortality in critical illness. Along with others, we hypothesize that reduction in morbidity and mortality observed in patients receiving insulin treatment is partially due to its effect on the attenuation of the immune response. However, there still remains substantial controversy regarding moderate versus intensive insulin treatment. Future studies need to determine the integrated effects of HG and insulin on the regulation of innate immunity in order to provide more effective insulin treatment regimen for these patients.

scholarly journals The Life Cycle Stages of Pneumocystis murina Have Opposing Effects on the Immune Response to This Opportunistic Fungal Pathogen

2016 ◽  
Vol 84 (11) ◽  
pp. 3195-3205 ◽  
Author(s):  
Heather M. Evans ◽  
Grady L. Bryant ◽  
Beth A. Garvy
Keyword(s):  
Cell Wall ◽  
Life Cycle ◽  
Immune Responses ◽  
Immune Cells ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Content Type ◽  
Life Cycle Stages ◽  
Ifn Γ

The cell wall β-glucans of Pneumocystis cysts have been shown to stimulate immune responses in lung epithelial cells, dendritic cells, and alveolar macrophages. Little is known about how the trophic life forms, which do not have a fungal cell wall, interact with these innate immune cells. Here we report differences in the responses of both neonatal and adult mice to the trophic and cystic life cycle stages of Pneumocystis murina . The adult and neonatal immune responses to infection with Pneumocystis murina trophic forms were less robust than the responses to infection with a physiologically normal mixture of cysts and trophic forms. Cysts promoted the recruitment of nonresident innate immune cells and T and B cells into the lungs. Cysts, but not trophic forms, stimulated increased concentrations of the cytokine gamma interferon (IFN-γ) in the alveolar spaces and an increase in the percentage of CD4 + T cells that produce IFN-γ. In vitro , bone marrow-derived dendritic cells (BMDCs) stimulated with cysts produced the proinflammatory cytokines interleukin 1β (IL-1β) and IL-6. In contrast, trophic forms suppressed antigen presentation to CD4 + T cells, as well as the β-glucan-, lipoteichoic acid (LTA)-, and lipopolysaccharide (LPS)-induced production of interleukin 1β (IL-1β), IL-6, and tumor necrosis factor alpha (TNF-α) by BMDCs. The negative effects of trophic forms were not due to ligation of mannose receptor. Our results indicate that optimal innate and adaptive immune responses to Pneumocystis species are dependent on stimulation with the cyst life cycle stage. Conversely, trophic forms suppress β-glucan-induced proinflammatory responses in vitro , suggesting that the trophic forms dampen cyst-induced inflammation in vivo .

scholarly journals Reprogramming Interferon Regulatory Factor Signaling in Cardiometabolic Diseases

Physiology ◽  
2017 ◽  
Vol 32 (3) ◽  
pp. 210-223 ◽  
Author(s):  
Yaxing Zhang ◽  
Hongliang Li
Keyword(s):  
Innate Immunity ◽  
Immune Responses ◽  
Immune Cells ◽  
Interferon Regulatory Factor ◽  
Innate Immune ◽  
Innate Immune Responses ◽  
Regulatory Factor ◽  
Cardiometabolic Diseases ◽  
Evolutionarily Conserved

Interferon regulatory factors (IRFs) are evolutionarily conserved proteins expressed not only in immune cells but also in other tissues and organs outside the immune system. In this review, we discuss mechanisms responsible for IRF-mediated innate immune responses and the function and mechanism of IRFs in cardiometabolic diseases. We focus on the role of IRFs in innate immunity and cardiometabolic homeostasis, and highlight reprogrammed IRF signaling.

scholarly journals Trained Immunity and Reactivity of Macrophages and Endothelial Cells

2020 ◽  
Author(s):  
Charles Drummer ◽  
Fatma Saaoud ◽  
Ying Shao ◽  
Yu Sun ◽  
Keman Xu ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Chronic Inflammation ◽  
Immune Cells ◽  
Metabolic Diseases ◽  
Tricarboxylic Acid Cycle ◽  
Density Lipoprotein ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Vaccine Response ◽  
Trained Immunity

Innate immune cells can develop exacerbated immunologic response and long-term inflammatory phenotype following brief exposure to endogenous or exogenous insults, which leads to an altered response towards a second challenge after the return to a nonactivated state. This phenomenon is known as trained immunity (TI). TI is not only important for host defense and vaccine response but also for chronic inflammations such as cardiovascular and metabolic diseases such as atherosclerosis. TI can occur in innate immune cells such as monocytes/macrophages, natural killer cells, endothelial cells (ECs), and nonimmune cells, such as fibroblast. In this brief review, we analyze the significance of TI in ECs, which are also considered as innate immune cells in addition to macrophages. TI can be induced by a variety of stimuli, including lipopolysaccharides, bacillus Calmette-Guerin, and oxLDL (oxidized low-density lipoprotein), which are defined as risk factors for cardiovascular and metabolic diseases. Furthermore, TI in ECs is functional for inflammation effectiveness and transition to chronic inflammation. Rewiring of cellular metabolism of the trained cells takes place during induction of TI, including increased glycolysis, glutaminolysis, increased accumulation of tricarboxylic acid cycle metabolites and acetyl-coenzyme A production, as well as increased mevalonate synthesis. Subsequently, this leads to epigenetic remodeling, resulting in important changes in chromatin architecture that enables increased gene transcription and enhanced proinflammatory immune response. However, TI pathways and inflammatory pathways are separated to ensure memory stays when inflammation undergoes resolution. Additionally, reactive oxygen species play context-dependent roles in TI. Therefore, TI plays significant roles in EC and macrophage pathology and chronic inflammation. However, further characterization of TI in ECs and macrophages would provide novel insights into cardiovascular disease pathogenesis and new therapeutic targets.

Latest Advances in Small Molecule TLR 7/8 Agonist Drug Research

2019 ◽  
Vol 19 (24) ◽  
pp. 2228-2238 ◽  
Author(s):  
David C. McGowan
Keyword(s):  
Immune Response ◽  
Innate Immunity ◽  
Small Molecule ◽  
Immune Cells ◽  
Drug Research ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Small Molecule Activation ◽  
Evolutionarily Conserved ◽  
Recent Developments

Toll-like receptors (TLRs) 7 and 8 play an important role in the activation of innate immune cells in mammals. These evolutionarily conserved receptors serve as important sentinels in response to infection. Activation of TLRs 7 and 8 triggers induction of a Th1 type innate immune response. The emergence of new structural and small molecule information generated in the last decade has contributed enormously to our understanding of this highly sophisticated process of innate immunity signaling. This review will focus on recent developments in the small molecule activation of TLR 7 and 8.

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